2021-07-10 21:49:00

19 files changed, 428 insertions, 33 deletions

diff --git a/tex/context/base/mkii/cont-new.mkii b/tex/context/base/mkii/cont-new.mkii
index 422bcf32a..f40536141 100644
--- a/tex/context/base/mkii/cont-new.mkii
+++ b/tex/context/base/mkii/cont-new.mkii
@@ -11,7 +11,7 @@
 %C therefore copyrighted by \PRAGMA. See mreadme.pdf for
 %C details.
 
-\newcontextversion{2021.07.09 18:13}
+\newcontextversion{2021.07.10 21:47}
 
 %D This file is loaded at runtime, thereby providing an
 %D excellent place for hacks, patches, extensions and new
diff --git a/tex/context/base/mkii/context.mkii b/tex/context/base/mkii/context.mkii
index 1cf730f4c..2b275f541 100644
--- a/tex/context/base/mkii/context.mkii
+++ b/tex/context/base/mkii/context.mkii
@@ -20,7 +20,7 @@
 %D your styles an modules.
 
 \edef\contextformat {\jobname}
-\edef\contextversion{2021.07.09 18:13}
+\edef\contextversion{2021.07.10 21:47}
 
 %D For those who want to use this:
 
diff --git a/tex/context/base/mkii/mult-it.mkii b/tex/context/base/mkii/mult-it.mkii
index a1f572ef5..99ae15d9a 100644
--- a/tex/context/base/mkii/mult-it.mkii
+++ b/tex/context/base/mkii/mult-it.mkii
@@ -1236,6 +1236,7 @@
 \setinterfaceconstant{splitoffset}{splitoffset}
 \setinterfaceconstant{spot}{spot}
 \setinterfaceconstant{stack}{stack}
+\setinterfaceconstant{stacking}{stacking}
 \setinterfaceconstant{stackname}{stackname}
 \setinterfaceconstant{start}{inizia}
 \setinterfaceconstant{starter}{starter}
diff --git a/tex/context/base/mkiv/cont-new.mkiv b/tex/context/base/mkiv/cont-new.mkiv
index 2d989531d..2e8e2ac4c 100644
--- a/tex/context/base/mkiv/cont-new.mkiv
+++ b/tex/context/base/mkiv/cont-new.mkiv
@@ -13,7 +13,7 @@
 
 % \normalend % uncomment this to get the real base runtime
 
-\newcontextversion{2021.07.09 18:13}
+\newcontextversion{2021.07.10 21:47}
 
 %D This file is loaded at runtime, thereby providing an excellent place for hacks,
 %D patches, extensions and new features. There can be local overloads in cont-loc
diff --git a/tex/context/base/mkiv/context.mkiv b/tex/context/base/mkiv/context.mkiv
index 30ae6b70f..be8e09179 100644
--- a/tex/context/base/mkiv/context.mkiv
+++ b/tex/context/base/mkiv/context.mkiv
@@ -45,7 +45,7 @@
 %D {YYYY.MM.DD HH:MM} format.
 
 \edef\contextformat {\jobname}
-\edef\contextversion{2021.07.09 18:13}
+\edef\contextversion{2021.07.10 21:47}
 
 %D Kind of special:
 
diff --git a/tex/context/base/mkiv/mult-def.lua b/tex/context/base/mkiv/mult-def.lua
index c097f2419..b6d6141e5 100644
--- a/tex/context/base/mkiv/mult-def.lua
+++ b/tex/context/base/mkiv/mult-def.lua
@@ -11810,6 +11810,10 @@ return {
    ["pe"]="توده",
    ["ro"]="stack",
   },
+  ["stacking"]={
+   ["en"]="stacking",
+   ["nl"]="stapels",
+  },
   ["stackname"]={
    ["en"]="stackname",
    ["fr"]="nompile",
diff --git a/tex/context/base/mkiv/mult-mps.lua b/tex/context/base/mkiv/mult-mps.lua
index 6512091ae..b4eba21a7 100644
--- a/tex/context/base/mkiv/mult-mps.lua
+++ b/tex/context/base/mkiv/mult-mps.lua
@@ -58,7 +58,7 @@ return {
         "prescriptpart", "postscriptpart",
         "rgbcolor", "cmykcolor", -- "greycolor", "graycolor",
         "colormodel",  "graypart", "greypart", "greycolor", "graycolor",
-        "dashpart", "penpart",
+        "dashpart", "penpart", "stackingpart",
 --         "colorpart",
         "stroked", "filled", "textual", "clipped", "bounded", "pathpart",
         "expandafter",
diff --git a/tex/context/base/mkiv/mult-prm.lua b/tex/context/base/mkiv/mult-prm.lua
index c3d0fa656..ae2b58a2a 100644
--- a/tex/context/base/mkiv/mult-prm.lua
+++ b/tex/context/base/mkiv/mult-prm.lua
@@ -307,6 +307,7 @@ return {
   "enforced",
   "etoksapp",
   "etokspre",
+  "everybeforepar",
   "everytab",
   "exceptionpenalty",
   "expand",
diff --git a/tex/context/base/mkiv/status-files.pdf b/tex/context/base/mkiv/status-files.pdf
index 8fb358fa4..4b9018dc7 100644
--- a/tex/context/base/mkiv/status-files.pdf
+++ b/tex/context/base/mkiv/status-files.pdf
diff --git a/tex/context/base/mkiv/status-lua.pdf b/tex/context/base/mkiv/status-lua.pdf
index 8e2064949..44e5059a7 100644
--- a/tex/context/base/mkiv/status-lua.pdf
+++ b/tex/context/base/mkiv/status-lua.pdf
diff --git a/tex/context/base/mkiv/symb-imp-was.mkiv b/tex/context/base/mkiv/symb-imp-was.mkiv
new file mode 100644
index 000000000..424e60b65
--- /dev/null
+++ b/tex/context/base/mkiv/symb-imp-was.mkiv
@@ -0,0 +1,206 @@
+%D \module
+%D   [       file=symb-was,
+%D        version=2005.10.15,
+%D          title=\CONTEXT\ Symbol Libraries,
+%D       subtitle=Roland Waldi's Symbols (wasy-2),
+%D         author=Henning Hraban Ramm,
+%D           date=\currentdate,
+%D      copyright={Public Domain}]
+%C
+%C This module is in the public domain.
+
+%D Converted to \MKIV\ by Hans but not yet complete.
+
+\unprotect
+
+\definefontsynonym [WaldiSymbol]     [wasy10]
+\definefontsynonym [WaldiSymbolBold] [wasyb10]
+
+% \def\wasy@over#1#2{{\setbox0\hbox{$#2$}\hbox to \wd0{\hss$#1$\hss}\kern-\wd0\box0}}
+
+\def\WaldiSymbol  {\getnamedglyphdirect{WaldiSymbol}} % #1
+\def\WaldiSymbol#1{\getglyph{WaldiSymbol}{\fontchar{#1}}}
+
+% general symbols
+
+\startsymbolset [wasy general]
+    \definesymbol [male]        [\WaldiSymbol{male}]
+    \definesymbol [female]      [\WaldiSymbol{female}]
+    \definesymbol [currency]    [\WaldiSymbol{currency}]
+    \definesymbol [cent]        [\WaldiSymbol{cent}]
+    \definesymbol [lozenge]     [\WaldiSymbol{lozenge}]
+    \definesymbol [kreuz]       [\WaldiSymbol{kreuz}]
+    \definesymbol [smiley]      [\WaldiSymbol{smiley}]
+    \definesymbol [blacksmiley] [\WaldiSymbol{blacksmil}]
+    \definesymbol [frownie]     [\WaldiSymbol{frownie}]
+    \definesymbol [sun]         [\WaldiSymbol{sun}]
+    \definesymbol [checked]     [\WaldiSymbol{checked}]
+    \definesymbol [brokenvert]  [\WaldiSymbol{brokenver}]
+    \definesymbol [diameter]    [\WaldiSymbol{diameter}]
+    \definesymbol [invdiameter] [\WaldiSymbol{invdiamet}]
+    \definesymbol [phone]       [\WaldiSymbol{phone}]
+    \definesymbol [recorder]    [\WaldiSymbol{recorder}]
+    \definesymbol [clock]       [\WaldiSymbol{clock}]
+    \definesymbol [permil]      [\WaldiSymbol{permil}]
+    \definesymbol [bell]        [\WaldiSymbol{bell}]
+    \definesymbol [ataribox]    [\WaldiSymbol{ataribox}]
+    \definesymbol [pointer]     [\WaldiSymbol{pointer}]
+    \definesymbol [lightning]   [\WaldiSymbol{lightning}]
+    \definesymbol [agemO]       [\WaldiSymbol{agemO}]
+\stopsymbolset
+
+\startsymbolset [wasy music]
+    \definesymbol [eighthnote]  [\WaldiSymbol{eighthnote}]
+    \definesymbol [quarternote] [\WaldiSymbol{quarternote}]
+    \definesymbol [halfnote]    [\WaldiSymbol{halfnote}]
+    \definesymbol [fullnote]    [\WaldiSymbol{fullnote}]
+    \definesymbol [twonotes]    [\WaldiSymbol{twonotes}]
+\stopsymbolset
+
+\startsymbolset [wasy astronomy]
+    \definesymbol [ascnode]     [\WaldiSymbol{ascnode}]
+    \definesymbol [descnode]    [\WaldiSymbol{descnode}]
+    \definesymbol [astrosun]    [\WaldiSymbol{astrosun}]
+    \definesymbol [sun]         [\WaldiSymbol{sun}]
+    \definesymbol [newmoon]     [\WaldiSymbol{newmoon}]
+    \definesymbol [fullmoon]    [\WaldiSymbol{fullmoon}]
+    \definesymbol [rightmoon]   [\WaldiSymbol{rightmoon}]
+    \definesymbol [leftmoon]    [\WaldiSymbol{leftmoon}]
+    \definesymbol [vernal]      [\WaldiSymbol{vernal}]
+    \definesymbol [mercury]     [\WaldiSymbol{mercury}]
+    \definesymbol [mars]        [\WaldiSymbol{mars}]
+    \definesymbol [saturn]      [\WaldiSymbol{saturn}]
+    \definesymbol [neptune]     [\WaldiSymbol{neptune}]
+    \definesymbol [earth]       [\WaldiSymbol{earth}]
+    \definesymbol [venus]       [\WaldiSymbol{venus}]
+    \definesymbol [jupiter]     [\WaldiSymbol{jupiter}]
+    \definesymbol [uranus]      [\WaldiSymbol{uranus}]
+    \definesymbol [pluto]       [\WaldiSymbol{pluto}]
+\stopsymbolset
+
+\startsymbolset [wasy astrology]
+    \definesymbol [conjunction] [\WaldiSymbol{conjunction}]
+    \definesymbol [opposition]  [\WaldiSymbol{opposition}]
+    \definesymbol [aries]       [\WaldiSymbol{aries}]
+    \definesymbol [libra]       [\WaldiSymbol{libra}]
+    \definesymbol [taurus]      [\WaldiSymbol{taurus}]
+    \definesymbol [scorpio]     [\WaldiSymbol{scorpio}]
+    \definesymbol [gemini]      [\WaldiSymbol{gemini}]
+    \definesymbol [sagittarius] [\WaldiSymbol{sagittarius}]
+    \definesymbol [cancer]      [\WaldiSymbol{cancer}]
+    \definesymbol [capricornus] [\WaldiSymbol{capricornus}]
+    \definesymbol [leo]         [\WaldiSymbol{leo}]
+    \definesymbol [aquarius]    [\WaldiSymbol{aquarius}]
+    \definesymbol [virgo]       [\WaldiSymbol{virgo}]
+    \definesymbol [pisces]      [\WaldiSymbol{pisces}]
+\stopsymbolset
+
+\startsymbolset [wasy geometry]
+    \definesymbol [fivestar]    [\WaldiSymbol{fivestar}] % HHR additional
+    \definesymbol [hexstar]     [\WaldiSymbol{hexstar}]
+    \definesymbol [varhexstar]  [\WaldiSymbol{varhexstar}]
+    \definesymbol [davidsstar]  [\WaldiSymbol{davidsstar}]
+    \definesymbol [Circle]      [\WaldiSymbol{Circle}]
+    \definesymbol [CIRCLE]      [\WaldiSymbol{CIRCLE}]
+    \definesymbol [Leftcircle]  [\WaldiSymbol{Leftcircle}]
+    \definesymbol [LEFTCIRCLE]  [\WaldiSymbol{LEFTCIRCLE}]
+    \definesymbol [Rightcircle] [\WaldiSymbol{Rightcircle}]
+    \definesymbol [RIGHTCIRCLE] [\WaldiSymbol{RIGHTCIRCLE}]
+%   \definesymbol [LEFTcircle]  [\dontleavehmode\hbox to \zeropoint{\WaldiSymbol {LEFTCIRCLE}\hss}\WaldiSymbol{Circle}]
+%   \definesymbol [RIGHTcircle] [\dontleavehmode\hbox to \zeropoint{\WaldiSymbol{RIGHTCIRCLE}\hss}\WaldiSymbol{Circle}]
+    \definesymbol [LEFTarrow]   [\WaldiSymbol{LEFTarrow}]
+    \definesymbol [RIGHTarrow]  [\WaldiSymbol{RIGHTarrow}]
+    \definesymbol [UParrow]     [\WaldiSymbol{UParrow}]
+    \definesymbol [DOWNarrow]   [\WaldiSymbol{DOWNarrow}]
+    \definesymbol [Box]         [\WaldiSymbol{Box}]
+    \definesymbol [APLbox]      [\WaldiSymbol{APLbox}]
+    \definesymbol [XBox]        [\WaldiSymbol{XBox}]
+    \definesymbol [Bowtie]      [\WaldiSymbol{Bowtie}]
+    \definesymbol [Diamond]     [\WaldiSymbol{Diamond}]
+    \definesymbol [octagon]     [\WaldiSymbol{octagon}]
+    \definesymbol [hexagon]     [\WaldiSymbol{hexagon}]
+    \definesymbol [varhexagon]  [\WaldiSymbol{varhexagon}]
+    \definesymbol [pentagon]    [\WaldiSymbol{pentagon}]
+%   \definesymbol [pentastar]   [\dontleavehmode\hbox to \zeropoint{\WaldiSymbol{pentagon}\hss}\lower.04em\hbox{\WaldiSymbol{fivestar}}]
+\stopsymbolset
+
+% \startsymbolset [wasy physics]
+%     \definesymbol [varangle]    [\WaldiSymbol{30}]
+%     \definesymbol [invneg]      [\WaldiSymbol{24}]
+%     \definesymbol [leftturn]    [\WaldiSymbol{34}]
+%     \definesymbol [rightturn]   [\WaldiSymbol{33}]
+%     \definesymbol [diameter]    [\WaldiSymbol{31}]
+%     \definesymbol [invdiameter] [\WaldiSymbol{21}] % additional
+%     \definesymbol [therefore]   [\WaldiSymbol {5}]
+%     \definesymbol [AC]          [\mbox{\kern.05em\WaldiSymbol{58}\kern.05em}]
+%     \definesymbol [HF]          [\dontleavehmode
+%                                  \lower.09em\hbox to \zeropoint{\kern.05em\WaldiSymbol{58}\hss}%
+%                                  \raise.09em\hbox{\kern.05em\WaldiSymbol{58}\kern.05em}]
+%     \definesymbol [VHF]         [\WaldiSymbol{64}]
+%     \definesymbol [photon]      [\hbox{\WaldiSymbol{58}\WaldiSymbol{58}\WaldiSymbol{58}\WaldiSymbol{58}}]
+%     \definesymbol [gluon]       [\hbox{\WaldiSymbol{80}\WaldiSymbol{80}\WaldiSymbol{80}\WaldiSymbol{80}\WaldiSymbol{80}\WaldiSymbol{80}}]
+% \stopsymbolset
+
+% \startsymbolset [wasy apl]
+%     \definesymbol [APLup]           [\WaldiSymbol{0}]
+%     \definesymbol [APLdown]         [\WaldiSymbol{70}]
+%     \definesymbol [APLbox]          [\WaldiSymbol{126}]
+%     \definesymbol [APLinv]          [\dontleavehmode\hbox to \zeropoint{$\div$\hss}\WaldiSymbol{126}]
+%     \definesymbol [APLleftarrowbox] [\WaldiSymbol{112}]
+%     \definesymbol [APLrightarrowbox][\WaldiSymbol{113}]
+%     \definesymbol [APLuparrowbox]   [\WaldiSymbol{110}]
+%     \definesymbol [APLdownarrowbox] [\WaldiSymbol{111}]
+%     \definesymbol [APLinput]        [\WaldiSymbol{125}]
+%     \definesymbol [APLminus]        [\dontleavehmode\raise.7ex\hbox{$-$}]
+%     \definesymbol [APLlog]          [\WaldiSymbol{22}]
+%     \definesymbol [APLstar]         [\WaldiSymbol{69}]
+%     \definesymbol [APLcomment]      [\WaldiSymbol{127}]
+%   % \definesymbol [notslash]        [\wasy@over{/}{-}]
+%   % \definesymbol [notbackslash]    [\wasy@over{\backslash}{-}]
+%   % %
+%   % %definesymbol [APLvert]         [\WaldiSymbol{}]
+%   % %definesymbol [APLnot]          [\WaldiSymbol{}]
+%   % %definesymbol [APLcirc]         [\WaldiSymbol{}]
+%   % %
+%   % % HH: messy, best define all combinations (todo)
+%   % %
+%   % \def\APLnot #1{\wasy@over{\sim }{#1}}
+%   % \def\APLcirc#1{\wasy@over{\circ}{#1}}
+%   % \def\APLvert#1{\wasy@over{\vert}{#1}}
+%   % %
+% \stopsymbolset
+
+\protect
+
+\continueifinputfile{symb-imp-was.mkiv}
+
+\usemodule[article-basic]
+
+\starttext
+
+\starttitle[title=Regular]
+
+    \startsubject[title={wasy general}]   \showsymbolset[wasy general]   \stopsubject
+    \startsubject[title={wasy music}]     \showsymbolset[wasy music]     \stopsubject
+    \startsubject[title={wasy astronomy}] \showsymbolset[wasy astronomy] \stopsubject
+    \startsubject[title={wasy astrology}] \showsymbolset[wasy astrology] \stopsubject
+    \startsubject[title={wasy geometry}]  \showsymbolset[wasy geometry]  \stopsubject
+
+\stoptitle
+
+\starttitle[title=Bold]
+
+    \startsubject[title={wasy general}]   \start \bf \showsymbolset[wasy general]   \stop \stopsubject
+    \startsubject[title={wasy music}]     \start \bf \showsymbolset[wasy music]     \stop \stopsubject
+    \startsubject[title={wasy astronomy}] \start \bf \showsymbolset[wasy astronomy] \stop \stopsubject
+    \startsubject[title={wasy astrology}] \start \bf \showsymbolset[wasy astrology] \stop \stopsubject
+    \startsubject[title={wasy geometry}]  \start \bf \showsymbolset[wasy geometry]  \stop \stopsubject
+
+\stoptitle
+
+
+% \startsubject[title={wasy physics}]   \showsymbolset[wasy physics]   \stopsubject
+% \startsubject[title={wasy apl}]       \showsymbolset[wasy apl]       \stopsubject
+
+\stoptext
+
diff --git a/tex/context/base/mkxl/cont-new.mkxl b/tex/context/base/mkxl/cont-new.mkxl
index 4fec9a7f9..974b7c4df 100644
--- a/tex/context/base/mkxl/cont-new.mkxl
+++ b/tex/context/base/mkxl/cont-new.mkxl
@@ -13,7 +13,7 @@
 
 % \normalend % uncomment this to get the real base runtime
 
-\newcontextversion{2021.07.09 18:13}
+\newcontextversion{2021.07.10 21:47}
 
 %D This file is loaded at runtime, thereby providing an excellent place for hacks,
 %D patches, extensions and new features. There can be local overloads in cont-loc
diff --git a/tex/context/base/mkxl/context.mkxl b/tex/context/base/mkxl/context.mkxl
index 4339426be..efba80182 100644
--- a/tex/context/base/mkxl/context.mkxl
+++ b/tex/context/base/mkxl/context.mkxl
@@ -29,7 +29,7 @@
 %D {YYYY.MM.DD HH:MM} format.
 
 \immutable\edef\contextformat {\jobname}
-\immutable\edef\contextversion{2021.07.09 18:13}
+\immutable\edef\contextversion{2021.07.10 21:47}
 
 %overloadmode 1 % check frozen / warning
 %overloadmode 2 % check frozen / error
diff --git a/tex/context/base/mkxl/meta-fig.mkxl b/tex/context/base/mkxl/meta-fig.mkxl
index b8a22f6fe..8348dfbaf 100644
--- a/tex/context/base/mkxl/meta-fig.mkxl
+++ b/tex/context/base/mkxl/meta-fig.mkxl
@@ -42,13 +42,16 @@
   [MPpage]
   [\c!align=,
    \c!command=\meta_process_graphic_command,
+   \c!stacking=,
    \c!instance=]
 
 \permanent\protected\def\setupMPpage
   {\setupfittingpage[MPpage]}
 
 \protected\def\meta_process_graphic_command
-  {\meta_process_graphic_instance{\fittingpageparameter\c!instance}}
+  {\meta_process_graphic_instance
+     {\fittingpageparameter\c!instance}%
+     {\fittingpageparameter\c!stacking}}
 
 %D \macros
 %D  {MPfigure}
diff --git a/tex/context/base/mkxl/meta-ini.mkxl b/tex/context/base/mkxl/meta-ini.mkxl
index def3900fe..8fca5d503 100644
--- a/tex/context/base/mkxl/meta-ini.mkxl
+++ b/tex/context/base/mkxl/meta-ini.mkxl
@@ -279,11 +279,12 @@
    \meta_relocate_graphic
    \popMPboundingbox}
 
-\protected\def\meta_process_graphic_instance#1%
+\protected\def\meta_process_graphic_instance#1#2% used in startMPpage
   {\edef\currentMPinstance{#1}%
    \ifempty\currentMPinstance
      \let\currentMPinstance\defaultMPinstance
    \fi
+   \setmpcategoryparameter\c!stacking{#2}%
    \edef\currentMPformat{\MPinstanceparameter\s!format}%
    \meta_process_graphic}
 
@@ -302,7 +303,7 @@
          inclusions      {\meta_flush_current_inclusions}%
          definitions     {\meta_flush_current_definitions}%
          figure          {\MPaskedfigure}%
-         filtering       {\mpcategoryparameter\c!list}
+         filtering       {\mpcategoryparameter\c!stacking}
          method          {\MPinstanceparameter\c!method}%
          namespace       {\??graphicvariable\currentmpcategory:}%
     \relax}%
@@ -661,7 +662,31 @@
 \permanent\protected\def\meta_start_unique_graphic_indeed#1#2#3\stopuniqueMPgraphic
   {\gdefcsname\??mpgraphic#1\endcsname{\meta_handle_unique_graphic{#1}{#2}{#3}}}
 
-\permanent\tolerant\protected\def\uniqueMPgraphic#=#*#=%
+% \permanent\tolerant\protected\def\uniqueMPgraphic#=#*#=%
+%   {\meta_begin_graphic_group{#1}%
+%    \checkmpcategoryparent
+%    \let\currentmpcategory\currentMPgraphicname
+%    \setupcurrentmpcategory[#2]%
+%    \begincsname\??mpgraphic#1\endcsname\empty
+%    \meta_end_graphic_group}
+
+\permanent\tolerant\protected\def\uniqueMPgraphic
+  {\futureexpandis[\meta_uniquempgraphic_yes\meta_uniquempgraphic_nop}
+
+\def\meta_uniquempgraphic_yes[#1]#*#=%
+  {% ugly code but we run on top of older code
+   \letdummyparameter\c!instance\empty
+   \getdummyparameters[#1]%
+   \edef\currentMPinstance{\dummyparameter\c!instance}%
+   % here we feed the instance into the analyzer
+   \meta_begin_graphic_group{\ifempty\currentMPinstance\else\currentMPinstance::\fi#1}%
+   \checkmpcategoryparent
+   \let\currentmpcategory\currentMPgraphicname
+   \setupcurrentmpcategory[#1]%
+   \begincsname\??mpgraphic#2\endcsname\empty
+   \meta_end_graphic_group}
+
+\def\meta_uniquempgraphic_nop#=#*#=%
   {\meta_begin_graphic_group{#1}%
    \checkmpcategoryparent
    \let\currentmpcategory\currentMPgraphicname
@@ -719,7 +744,51 @@
 \protected\def\meta_start_reusable_graphic_indeed#1#2#3\stopreusableMPgraphic
   {\gdefcsname\??mpgraphic#1\endcsname{\meta_handle_reusable_graphic{#1}{#2}{#3}}}
 
-\permanent\tolerant\protected\def\useMPgraphic#=#*#=%
+% \permanent\tolerant\protected\def\useMPgraphic#=#*#=%
+%   {\meta_begin_graphic_group{#1}%
+%    \ifcsname\??mpgraphic#1\endcsname
+%      \edef\currentmpcategory{#1}%
+%    \orelse\ifcsname\??mpgraphic\currentMPgraphicname\endcsname
+%      \let\currentmpcategory\currentMPgraphicname
+%    \else
+%      \let\currentmpcategory\empty
+%    \fi
+%    \ifempty\currentmpcategory
+%      % message
+%    \else
+%      \checkmpcategoryparent
+%      \doifsomething{#2}{\setupcurrentmpcategory[#2]}%
+%      \csname\??mpgraphic\currentmpcategory\endcsname
+%    \fi
+%    \meta_end_graphic_group}
+
+\permanent\tolerant\protected\def\useMPgraphic
+  {\futureexpandis[\meta_usempgraphic_yes\meta_usempgraphic_nop}
+
+\def\meta_usempgraphic_yes[#1]#*#=%
+  {% ugly code but we run on top of older code
+   \letdummyparameter\c!instance\empty
+   \getdummyparameters[#1]%
+   \edef\currentMPinstance{\dummyparameter\c!instance}%
+   % here we feed the instance into the analyzer
+   \meta_begin_graphic_group{\ifempty\currentMPinstance\else\currentMPinstance::\fi#2}%
+   \ifcsname\??mpgraphic#2\endcsname
+     \edef\currentmpcategory{#2}%
+   \orelse\ifcsname\??mpgraphic\currentMPgraphicname\endcsname
+     \let\currentmpcategory\currentMPgraphicname
+   \else
+     \let\currentmpcategory\empty
+   \fi
+   \ifempty\currentmpcategory
+     % message
+   \else
+     \checkmpcategoryparent
+     \setupcurrentmpcategory[#1]%
+     \csname\??mpgraphic\currentmpcategory\endcsname
+   \fi
+   \meta_end_graphic_group}
+
+\def\meta_usempgraphic_nop#=#*#=%
   {\meta_begin_graphic_group{#1}%
    \ifcsname\??mpgraphic#1\endcsname
      \edef\currentmpcategory{#1}%
@@ -892,7 +961,22 @@
 %D
 %D The most simple case:
 
-\permanent\tolerant\protected\def\startMPcode#=#:#2\stopMPcode
+% \permanent\tolerant\protected\def\startMPcode#=#:#2\stopMPcode
+%   {\begingroup
+%    \edef\currentMPinstance{#1}%
+%    \ifempty\currentMPinstance
+%      \let\currentMPinstance\defaultMPinstance
+%    \fi
+%    \let\currentMPgraphicname\empty
+%    \edef\currentMPformat{\MPinstanceparameter\s!format}%
+%    \meta_enable_include
+%    \meta_process_graphic{#2}%
+%    \endgroup}
+
+\permanent\tolerant\protected\def\startMPcode
+  {\futureexpandis[\meta_start_mpcode_yes\meta_start_mpcode_nop}
+
+\tolerant\def\meta_start_mpcode_nop#:#=#:#2\stopMPcode
   {\begingroup
    \edef\currentMPinstance{#1}%
    \ifempty\currentMPinstance
@@ -904,6 +988,22 @@
    \meta_process_graphic{#2}%
    \endgroup}
 
+\def\meta_start_mpcode_yes[#1]#2\stopMPcode
+  {\begingroup
+   \letdummyparameter\c!instance\empty
+   \letdummyparameter\c!stacking\empty
+   \getdummyparameters[#1]%
+   \edef\currentMPinstance{\dummyparameter\c!instance}%
+   \setmpcategoryparameter\c!stacking{\dummyparameter\c!stacking}%
+   \ifempty\currentMPinstance
+     \let\currentMPinstance\defaultMPinstance
+   \fi
+   \let\currentMPgraphicname\empty
+   \edef\currentMPformat{\MPinstanceparameter\s!format}%
+   \meta_enable_include
+   \meta_process_graphic{#2}%
+   \endgroup}
+
 \permanent\protected\lettonothing\stopMPcode
 
 %D This one is not optimized because it's only used for small snippets, if it
diff --git a/tex/context/base/mkxl/mlib-pdf.lmt b/tex/context/base/mkxl/mlib-pdf.lmt
index 11f211b2b..58a1129eb 100644
--- a/tex/context/base/mkxl/mlib-pdf.lmt
+++ b/tex/context/base/mkxl/mlib-pdf.lmt
@@ -388,7 +388,7 @@ function metapost.flush(specification,result)
             local textfigure         = flusher.textfigure
          -- local processspecial     = flusher.processspecial or metapost.processspecial
             local tocomment          = flusher.tocomment
-            if type(filtering) ~= "table" then
+            if type(filtering) ~= "table" or not next(filtering) then
                 filtering = false
             end
             -- patterns: we always use image 1 and then can use patterns for 2..n (or one number)
diff --git a/tex/context/base/mkxl/mlib-pps.lmt b/tex/context/base/mkxl/mlib-pps.lmt
index 7790f0f23..cea8a179d 100644
--- a/tex/context/base/mkxl/mlib-pps.lmt
+++ b/tex/context/base/mkxl/mlib-pps.lmt
@@ -6,6 +6,7 @@ if not modules then modules = { } end modules ['mlib-pps'] = {
     license   = "see context related readme files",
 }
 
+local next = next
 local format, gmatch, match, split, gsub = string.format, string.gmatch, string.match, string.split, string.gsub
 local tonumber, type, unpack, next, select = tonumber, type, unpack, next, select
 local round, sqrt, min, max, abs = math.round, math.sqrt, math.min, math.max, math.abs
@@ -592,9 +593,13 @@ function metapost.graphic_base_pass(specification)
     top.data              = data
     top.initializations   = initializations
     if filtering then
-        local t = { }
-        stepper(filtering,function(k) t[k] = true end)
-        filtering = t
+        if #filtering > 0 then
+            local t = { }
+            stepper(filtering,function(k) t[k] = true end)
+            filtering = next(t) and t or false
+        else
+            filtering = false
+        end
     end
     if trace_runs then
         report_metapost("running job %s, asked figure %a",nofruns,askedfig)
@@ -1558,15 +1563,19 @@ end
 -- groups
 
 local function getcorners(path)
-    local p1 = path[1]
-    local p2 = path[2]
-    local p3 = path[3]
-    local p4 = path[4]
-    return
-        min(p1.x_coord,p2.x_coord,p3.x_coord,p4.x_coord),
-        min(p1.y_coord,p2.y_coord,p3.y_coord,p4.y_coord),
-        max(p1.x_coord,p2.x_coord,p3.x_coord,p4.x_coord),
-        max(p1.y_coord,p2.y_coord,p3.y_coord,p4.y_coord)
+--     if #path == 1 then
+--         return 0, 0, 0, 0
+--     else
+        local p1 = path[1]
+        local p2 = path[2]
+        local p3 = path[3]
+        local p4 = path[4]
+        return
+            min(p1.x_coord,p2.x_coord,p3.x_coord,p4.x_coord),
+            min(p1.y_coord,p2.y_coord,p3.y_coord,p4.y_coord),
+            max(p1.x_coord,p2.x_coord,p3.x_coord,p4.x_coord),
+            max(p1.y_coord,p2.y_coord,p3.y_coord,p4.y_coord)
+--     end
 end
 
 local function gr_process(object,prescript,before,after)
diff --git a/tex/context/base/mkxl/syst-ini.mkxl b/tex/context/base/mkxl/syst-ini.mkxl
index c13e5eaef..15e349330 100644
--- a/tex/context/base/mkxl/syst-ini.mkxl
+++ b/tex/context/base/mkxl/syst-ini.mkxl
@@ -16,13 +16,77 @@
 %D this loader is found in \type {syst-tex.tex}. Some of the comment's are Don
 %D Knuths and more of it can be found in the plain \TEX\ format.
 %D
+%D Successive versions will be adapted to \LUAMETATEX. That also means that we
+%D define things a bit differently than in \MKII\ and \MKIV. This is party due to
+%D the fact that in this engine we removed some side effects or added features. The
+%D original \TEX\ program is well defined and documented and is still the benchmark.
+%D The \ETEX\ extensions originally were meant as systematic follow up but that
+%D never went beyond a first upgrade. It had a dual mode: compatible or extensible.
+%D We always used the second mode. The \LUATEX\ engines don't have that.
+%D
+%D There are some hard coded properties that relate to for instance node types but
+%D we always used abstraction. There are also side effects that (probably) originate
+%D in the fact that \ETEX\ had to stay compatible with the dominant set of macros
+%D using the original \TEX\ ones (either or not wrapped). Even unwanted side effects
+%D eventually become features. In\LUATEX\ and even more in \LUAMETATEX\ we get
+%D around that by additional mode variables that you can find below.
+%D
+%D Side note: those who complain about \TEX\ as rather special language, \ETEX\
+%D extensions that should have been or be different, should really look into how
+%D \TEX\ and friends evolved, and not come to quick and wrong conclusions. There are
+%D only a very few languages that evolve this way. As a comparison one can wonder
+%D why \CCODE\ never had proper strings like \PASCAL\ bit it's just hindsight and
+%D discussing it has no use. In a similar fashion one should keep in mind that what
+%D you see here is just a logical follow up in \MKII\ where we had to bend the rules
+%D and \MKIV\ where we had a bit more available. Not many who look at the latest
+%D engines had to jump though all the hoops.
+%D
+%D This is for instance noticeable in the names of some primitvies: \CONTEXT\ has a
+%D concept of protection before \type {\protected} showed up, and similarly had
+%D expansion helpers. This is why in \MKII\ you find \type {\protected}, \type
+%D {\expanded}, and \type {\unexpanded} commands with different meanings than the
+%D later \ETEX\ primitives. In \MKIV\ we stuck to the \CONTEXT\ originals and use
+%D \type {\normal...} ones when needed (so \type {\normal...} is there for a
+%D reason!). In \LMTX\ we made the transition from \type {\unexpanded} to \type
+%D {\protected} so again this file looks different than the \MKIV\ ancestor.
+%D
+%D When primitives get initialized they come from the \TEX\ namespace (the
+%D originals), the \ETEX\ extensions (although we dropped some) and \LUATEX\ which
+%D includes the \LUAMETATEX\ ones. The most noticeable \ETEX\ extensions we kept are
+%D those that relate to expansion and the expression scanners. The last group has
+%D always been somewhat special because (we were told) it was modelled after a macro
+%D set so it had to be compatible. It is tempting to replace it (and eventually I
+%D might do that) but for now we stick to them (although with an integer divide
+%D extension (like the \LUA\ \type {//} and the source has commented binary
+%D operators but I haven't yet decided on the symbols to use because we need to
+%D avoid expansion issues). For the record: the more extensive, related to \ETEX\
+%D follow up \NTS\ never took of, probably because of the implementation language
+%D and because performance made it unuseable. This is also why \LUATEX\ took a
+%D different route: extending by an extension language. Of course in the end some
+%D core functionality got added too.
+%D
+%D The most noticeable \LUAMETATEX\ specific code here has to do with additional
+%D data types (integer and dimension constants) and macro argument extensions. We
+%D also set up some defaults in handling math, languages, etc. Elsewhere in the
+%D \CONTEXT\ source the real configuration and usage happens so don't consider this
+%D an tutorial (as the plain format is).
+%D
+%D Category codes are another areas where subtle changed happened. You might not
+%D grasp it (maybe because \CONTEXT\ is alien to you) but whenever you see something
+%D that looks weird keep in mind that there is a valid reason for it.
+%D
+%D In due time I will add some more comments here, also because some \CONTEXT\
+%D users might be interested in the hostiry. Now to the code!
+
 %D Characters can have special states, that can be triggered by setting their
 %D category coded. Some are preset, others are to be set as soon as possible,
 %D otherwise we cannot define any useful macros.
 %D
 %D First we define a bunch of constants. Normally we would \type {\setconstant}
 %D but we're prestine and have no macros defined yet. Abstraction also makes it
-%D possible to avoid the \type {^^} in the input.
+%D possible to avoid the \type {^^} in the input. We no longer define the \ETEX\
+%D nodes here (we have not only more, but also different numbers) so we do it
+%D elsewhere.
 
 % cheatsheet
 %
@@ -311,7 +375,10 @@
 %D consecutive ranges more easily, for instance if for \MPLIB\ we want to allocate a
 %D continuous range of boxes. It also permits us to do a proper upward allocation
 %D for inserts. The current code evolved from code that dealt with older engines but
-%D as all engines now provide many registers we removed all traces.
+%D as all engines now provide many registers we removed all traces. If you ever run
+%D into the \MKII\ \type {mptopdf} code, you'll notice that some register magic was
+%D needed to fit into existing macro packages. The same is true for \PICTEX\ that we
+%D used in (gheneric) \PPCHTEX.
 
 \ifdefined\writestatus \else
    %\protected\def\writestatus#1#2{\immediate\write\statuswrite{#1: #2}}
@@ -563,8 +630,8 @@
   {\showboxdepth  \plusthree
    \showboxbreadth\plusfive}
 
-%D Some expected plain variants follow. We don't reuse registers because we
-%D don't want clashes.
+%D Some expected plain variants follow. We don't reuse registers because we don't
+%D want clashes. These will go away and packages that need them have to define them.
 
 \aliased\let\p@     \onepoint
 \aliased\let\m@ne   \minusone
@@ -639,9 +706,12 @@
 \newif\ifscratchconditionone
 \newif\ifscratchconditiontwo
 
+%D This used to be a protected definition with a \type {dimexpr} but now we have
+%D it natively (less tracking noise).
+
 \aliased\let\htdp\boxtotal
 
-%D A few shortcuts:
+%D A few shortcuts (gone by now):
 
 % \permanent\protected\def\udef {\protected\def }
 % \permanent\protected\def\ugdef{\protected\gdef}
@@ -660,7 +730,7 @@
 \permanent\protected\def\defUmathchar       #1#2#3#4{\global\immutable\Umathchardef #1                  "#2 "#3 "#4 }
 
 %D For a while we keep the following, as systems like tikz need it. Best not use
-%D that one \CONTEXT.
+%D that one \CONTEXT. It will probably move to the tikz loader.
 
 \aliased\let\active\activecatcode
 
@@ -1177,7 +1247,7 @@
   {\ifflags#2\permanent\permanent\fi % the rest is taken with the copy
    \def#1{\syst_suggested_alias#1#2}}
 
-% A few traditional allocations (these might go):
+% A few traditional allocations (these might go too):
 
 % \countdef \count@   255 % hm, used in \newif .. todo: replace it there
 % \dimendef \dimen@     0
diff --git a/tex/context/interface/mkii/keys-it.xml b/tex/context/interface/mkii/keys-it.xml
index 43db8cfc1..db0dee470 100644
--- a/tex/context/interface/mkii/keys-it.xml
+++ b/tex/context/interface/mkii/keys-it.xml
@@ -1242,6 +1242,7 @@
 		<cd:constant name='splitoffset' value='splitoffset'/>
 		<cd:constant name='spot' value='spot'/>
 		<cd:constant name='stack' value='stack'/>
+		<cd:constant name='stacking' value='stacking'/>
 		<cd:constant name='stackname' value='stackname'/>
 		<cd:constant name='start' value='inizia'/>
 		<cd:constant name='starter' value='starter'/>